Method of and apparatus for firing the furnaces of steam generators and other furnaces



Sept. 16. 1924. 1,508,393

J. A. HILL METHOD OF AND APPARATUS FOR. FIRING THE. FURNACES OF STEAM GENERATORS AND OTHER FURNACES Filed Jan. 5, 1923 3 Sheets-Sheet l @W ifi 6/ ES OF STEAM GENERATORS Sept. 16 1924.

J. A. HILL METHOD OF AND APPARATUS FOR FlRING THE FURNAC- AND OTHER FURNACES Filed Jan. 5, 1923 5 Shaman-Sheet 2 FIGZ.

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- J. A. HILL METHOD OF AND APPARATUS FOR FIRING THE FURNACES OF STEAM GENERATORS AND OTHER FURNACES Filed Jan. 5. 1.923 s sheets shaot :5

- u B cu 0 is 3a JOSEPH ALBERT HILL, DECEASED, LATE OF DAR-LEY DALE, ENG-LAND; BY MRS. SARAH ANN HILL, EXECUTRIX.

METHOD OF AND APPARATUS FOR FIRING THE IEYJZRJZLACES OF STEAM GENERATORS AND OTHER, FURNACES.

Application filed January 8, 1923.

Derby, England, did invent a certain new anduseful Improved Method of and Apparatus for Firing the Furnaces of Steam Generators and Other Furnaces, and I, ALFRED PERCY HILL, a subject of the King of Great Britain, residing at Darley Dale, in the county of Derby, England, whose post-ofiice address is Darley House, Darley Dale, aforesaid, executor of the last will and testament of the said JOSEPH ALBERT HILL, deceased, do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

The present invention relates principally to the furnaces of steam generators for 10- comotive boilers and the like, but the invention is not restricted to such furnaces as it is also applicable in its main features to furnaces of other steam generators as well as to industrial furnaces such, for instance, as those usually employed in the manufacture of steel. Heretofore a disadvantage in actual. practice with furnaces having grates capable of burning inferior solid fuel has been that they cannot maintain the combustion of such fuel for considerable periods of time, owing to the rapid accumulation of incombustible material on the fire grate, and in consequence the full output of a locomotive or other steam generator fitted with such furnaces cannot be obtained.

, The present invention has for its object the provision of a furnace comprising means whereby not only is the above-mentioned disadvantage eliminated but it is also possible to effectively burn (1) ordinary steam coal (2) to effectively burn any solid fuel of an inferior character such for instance as peat, lignite, slack or any other solid fuel having a high ash, silicate or iron content, or (3) to effectively burn liquid fuel only, and (4) to effectively burn any inferior solid fuel and any suitable liquid fuel at one and the same time.

With the above object in view the invention consists principally .in a furnace comprising a fire-grate consisting of closely spaced fire-bars carried by the open tops or Serial No. 610,541.

upper sides of a number of air andsteam conduits open at one end and arranged alongside each other immediately below said grate,

a liquid fuel burner or burners adapted to deliver liquid fuel to the furnace chamber, steam jet nozzles adapted and arranged to deliver steam into the open ends of the said conduits and to thereby inject air into the conduits and thence to the underside of the fire grate, steam pipe connections to the said steam jet-nozzles, a valve or valves for controlling the supply of steam to the said nozzles, and valves for controlling the supply of liquid fuel to the liquid fuel burners.

Further according to this invention, in the preferred embodiment thereof, the above mentioned steam and air conduits below and supporting the fire-grate are arranged in two sets one behind the other, the conduits of each set being open at their ends remote from the fire door hole and each set of'conduits has its own set of steam jet nozzles with independent steam supply pipes and regulating valves for supplying steam to each set of nozzles. Further the said steam jet nozzles are preferably annular nozzles constructed and arranged so that they project into the open ends of the aforesaid air and steam conduits as hereinafter more fully described, and the said open ends of the conduits are preferably bell-mouthed or conical in form and each said bell-mouthed or conical end is preferably constituted by a fitting secured to the open end of the respective conduit.

Further according to this invention, in its application to the furnace or fire-box of a boiler, the open ends of the aforesaid steam and air conduits of both the forward and rear sets of such conduits, and the steam jet nozzles for injecting air and delivering steam into the said conduits are situated within a chamber having air admission openings controlled by doors or dampers; this chamber, in the case of a locomotive firebox, being the usual ash pan or box.

The steam pipes through which steam issupplied to the sets of steam et nozzles above mentioned may each be connected to the steam space of the boiler through a sultable hand operable valve, but are preferably, inthe case of a locomotive boiler, connected with the superheated steam side of chamber of the usual or any suitable steam super-heater as generally fitted in connection with the boiler, branch pipes leading from each of the said steam supply pipes to the respective sets of steam jet nozzles of the steam and air conduits above-mentioned.

In addition to the usual fire-door hole or opening for feeding or shovelling solid fuel into the fire-box a suitable number of apertures is provided in the back plate of the boiler and in the fire-door plate of the fire-box or furnace chamber, preferably below the said fire-hole opening, and in each of these apertures there is fitted the supply nozzle or jet of any suitable or well known liquid fuel burner to which burners liquid fuel is supplied as usual through suitable control valves in the pipe connections leading from an oil tank carried, in the case of alocomotive, on the tender which is also provided with a suitable space forming a receptacle for the solid fuel.

The invention further consists in a furnace comprising the various devices constructed, combined or arranged and adapted to operate substantially as and for the purposes described with reference to and illustrated in the accompanying drawings, in which Fig. 1 is a longitudinal sectional elevation of the fire-box of a locomotive boiler fitted with furnace equipment suitable for the burning of either high grade or good steam coal only, inferior solid fuel only, liquid fuel only, or both inferior solid fuel and liquid fuel at the same time.

Fig. 2 is an elevation of part of the back plate of the locomotive boiler shown in Fig. 1, and

Fig. 3 is a sectional plan view of the furnace or fire-box shown in Fig. 1 the section being taken on the line Al3 Fig. 1.

Fig. lis a longitudinal section of the annular steam jet nozzle hereinafter described.

Like reference numbers indicate corresponding parts in the several figures of the drawings.

1 indicates a portion of the barrel of a locomotive boiler, 2 and 2* the fire-cox plates, and 3 the usual back plate of the boiler, the plate 2 being known as the firedoor plate. 4 is the. usualfire hole opening through the back plate 3 and fire-door plate 2 through which solid fuel is passed on to the fire, grate within the furnace chamber or fire-box. As clearly shown in Figs. 1 and 3 the fire-grate within the furnace chamber of the fire-box consists of a number of conduits 5 and 5 arranged side by side and longitudinally of the fire-box, there being, in the example shown, two sets of these conduits one set arranged in advance of the other and each set comprising four conduits each of which carries at its upper side, which is otherwise open, a suitable number of closely spaced lire bars 6. Each of the conduits 5, 5 is open at its end remote fromthe fire-door plate 2 as clearly shown in Fig. 1 and is there provided with a fitting 7, which may be a casting riveted or bolted to the end of the conduit, the said fitting having a flared or bell-mouthed or conical opening 8 at its outer end and constituting a steam and air inlet to the respective conduits 5, 5 9, 9 are the hereinbefore-inentioned annular steam jet nozzles which project into the fittings 7 and to which steam is supplied respectively through the pipes 10, 10 the admission of steam to which is controlledby hand valves respectively 11, 11 (Fig. 2) in a fitting 12 to which steam is supplied, preferably from the usual steam superheater, through a pipe 13. As clearly shown in Figs. 1 and 3 of the drawings there are four steam jet nozzles 9 constituting a set of nozzles appertaining to the conduits 5, and four steam jet nozzles 9 constituting a set of nozzles appertaining to the conduits 5.

In th closed ends of the conduits 5, 5 adjacent to the firedoor plate 9" suitable channels let, 14, respectively, (Fig. 1) are provided from which small apertures open into the said conduits, and provision is made for supplying high pressure water from the water space of the boiler to the said channels 14:, 1 1 of the several conduits through branch pipes respectively 15, 15 which are supplied with water through the pipe connections 16, 17 the passage of water from the boiler through the latter pipes being controlled by a suitable manually operated valve 18 1 and 2).

Each of the before-mentioned annular steam jet nozzles 9, as shown, consists of inner and outer concentrically arranged tubular parts 19, 19 of suitable diameter so that between the parts 19 and 19" an annular space 20 is provided which is closed at one end by a solid ring 21 of steel or other suitable metal which ring may be acetylene welded to the ends of the said inner and outer tubes, and to the opposite end of the said concentric tubular parts 19, 19 a rin 22 of steel or other suitable metal b is secured (for instance welded thereto by .OXY-HCGtYlGDQ welding) this ring 22 having formed in it an annular series of steam jet orifices or holes 29f leading from the annular space 20 through the ring 22, so as to deliver a number of steam jets into the conduits 5, 5, respectively, as indicated in Fig. 1 of the drawings. As shown in Fig. 1 the steam jet ring 22 has its inner periphery so formed that it embraces a space of truncated cone shape with its greatest diameter at the extreme outer end of the nozzle, the ring 21 at the opposite end being similarly formed, or, as shown in the drawing, formed so as to provide a flared or bell mouth for the inlet of air to the inner tubular part 19. The steam jet nozzles 9, 9 as above described provide in a highly efficient manner for adequate supply of steam and air to the conduits 5, 5 and conse quently to the underside of the fire-bars 6, the central passage through the said steam jet devices 9, 9 embraced by the inner tubular member 19 as well as the space surrounding the outer tubular member 19 between it and the aforesaid fitting 7 constituting passages through which an adequate supply of air will be effectively delivered into the conduits respectively 5, 5 by the action of the steam jet nozzle devices 9, 9

23 (Fig. 1) indicates the ashpan below the fire-grate or fire-bars 6 as usual in the case of a locomotive boiler furnace, 24, 25 and 26 (Fig. 1) being-doors or dampers which can be opened more or less, as de sired, by means of suitable mechanical connections from the said doors to the footplate, the said connections being, in known manner, so arranged that the doors or dampers can be controlled independently.

27 (Fig. 1) indicates one of two openings or ducts (if desired there may be more than two of such openings or ducts) provided in the back-plate 3 and in the fire-box door plate 2 into each of which openings or ducts is fitted the nozzle of any suitable or well known liquid fuel burner 28 to which liquid fuel is supplied through pipe connections, indicated. at 29 (Fig. 2), which receive liquid fuel from the supply tank carried on the tender, known or'suitable controlling valves being as usual provided in the pipe connections 29 between the burners 28 and the said supply tank.

By providing for thesupply of liquid fuel to the fire-box or furnace chamber of a furnace fitted with a grate suitable for the combustion of inferior solid fuel the engineman is enabled to provide, when occasion requires, a fuel of high calorific value to make up for the loss of "combustibles which occurs when the grate has become made up orchoked with ash, iron pyrites, slack and other residue of the inferior fuel, and by providing efficient means for maintaining an adequate supply of steam and air to the fire-grate the residues from the inferior fuel can be kept in such a porous condition as to permit of an adequate supply of air to the furnace chamber to maintain efficient combustion.

The construction and arrangement of the conduits 5, 5 and of the combined steam jet and air injector nozzles 9, 9 and their associated parts, as well as of the liquid fuel burners 28, is such that no material structural alteration of existing fire boxes or furnaces is necessary in order to convert such a fire-box or furnace into a furnace according to this invention, whereby, as before-mentioned, various kinds and grades or qualities of solid fuel can be efficiently utilized, or liquid fuel only can be efficiently utilized, or both liquid fuel and solid fuel of low grade or inferior quality can be efliciently utilized. In the case of a locomotive which has to travel into territory where only inferior solid fuel is obtainable a furnace according to this invention is highly advantageous inasmuch as the 'engineman can, with the simultaneous use of such inferior fuel and the liquid fuel which he can supply .to the furnace, efiectively work his engine with maximum loads.

Further by means of this invention the advantages obtained by the use of colloids as fuel are obtained in a highly efiicient and economical manner without the necessity and expense of preparing the colloids for use; in other words economies heretofore derived by the grinding of inferior solid fuels and mixing the latter with liquid fuel before use in a furnace are obtained with the furnace according to this invention by the direct firing of inferior solid fuel to the fire-box or furnace chamber while at the same time supplying sufficient liquid fuel to provide for maximum loads. When using ordinary steam coal or other solid fuel alone (that is to say without at the same'time supplying liquid fuel to the furnace chamber) the grate, consisting of the hereinbefore mentioned transverse'fireliquid fuel burner jets is preferably lightly strewn with suitable. refractory material the remaining portion-of the grate in this case beingutilized for the purpose of receiving the solid fuel. Further when solid fuel only is used steam is admitted to all the steam jets and air injectors 9, 9 of all the conduits 5, 5. When using solid fuel and liquid fuel at the same time, steam is admitted only to the set of steam jets 9 appertaining to the conduits 5 It has been found from actual test of a furnace according to this invention that by the employment of annular steam jet nozzles such as 9, 9 projecting well into the bell-mouthed or conical ended fittings 7 of the conduits 5, 5 as illustrated in the draw ings, a highly efficient injector action is obtained whereby an adequate supply of air and steam to the conduits 5, 5 and to the under side of the fire bars is ensured.

By the provision of the hereinbefore mentioned channels 14, 14 in the ends of the conduits 5, 5 together with the pipes 17,15 and 15 hereinbefore referred to, the conduits 5, 5 can be flushed down by the admission thereto of high pressure water from the boiler thus clearing away ash or refuse which has fallen through the firegrate or fire-bars 6 into the conduits. By this means the conduits are kept clean and free for admission of air induced or injected by the steam issuing from the steam jet devices 9, 9

If desired the openings or ducts 27 with the liquid fuel burners 28 may be situated somewhat nearer to the fire bars 6 than shown in Fig. 1 of the drawings, and in this case an arch of suitable refractory material may be provided between the fire hole opening a and the ducts 27 such arch eX- tending a suitable distance from the fire door plate 2 into the furnace chamber for the purpose of preventing solid fuel, introduced through the fire-door hole f, falling in front of the liquid fuel burner, and also for the purpose of increasing the radiant heat for ignition of the oil introduced by the nozzles of the liquid fuel burners 28.

Further, if desired a steam superheater pipe or element may be inserted in the firebox or furnace chamber adjacent to the firedoor plate 2 for the purpose of superheating the steam supplied to the said pipe from the boiler, through a suitable control valve, which. steam may pass through the usual or suitably arranged steam pipes connected with the usual steam inlets of the liquid fuel burners and be used for the atomization of the liquid fuel issuing from the nozzles of the liquid fuel burners 28 into the fire-box. This steam superheating pipe may be also employed for supplying superheated steam to the steam jet and air injector nozzles 9, 9 in cases where the boiler is not fitted with the usual steam superheater for supplying superheated steam to the engine cylinders.

The hereinbefore mentioned conduits 5, 5 may be of any suitable shape in cross section, for instance they may be U-shape in cross section, and the said conduits with the fire-bars 6 carried thereby, or the firebars 6 may, if desired, be so constructed and arranged in conjunction with suitable operating gear or mechanism that the said conduits, or the fire-bars, can be rocked or shaken.

Modifications might be made in the details of construction and arrangement of the parts comprised in the improved furnace as above described without departing from the invention.

What I claim is 1. In a furnace, a fire-box, two series of conduits arranged end to end in the firebox, the conduits of each series being arranged side by side and provided with grates at their tops and downwardly and rearwardly inclined bottoms and having openings at their rear ends, the front ends of the rear conduits being secured to the rear ends of the front conduits above the evel of the openings of the latter, and means for forcing steam and air into each conduit through the opening at its rear end.

2. In a furnace, the combination, with the parts set forth in claim 1, of an ash pan common to both series of conduits.

8. In a furnace, the combination, with the parts set forth in claim 1, of a closed ash pan common to both series ofconduits and provided with means for regulating the entrance of air into it to supply the conduits.

4.. In a furnace, the combination, with the parts set forth in claim 1, of means for admitting water under pressure to the front and upper end of each conduit.

In a furnace, the combination, with the parts set forth in claim 1, of means for introducing liquid fuel into the fire-box at its front end and above the level of the tops of the said grates.

6. In a furnace, the combination, with the parts set forth in claim 1, of bell-mouthed fittings secured around the openings at the rear ends of the conduits, and the said means for forcing steam and air into the conduits comprising tubular injectors arranged in the bell-morithed fittings and havino: central air passages.

In testimony whereof I aflix my signature. I

ALFRED PER-CY HILL, Executor 0f the Zest will and testament of asap-7i Albert Hill, deceased. 

